Image Sequence Texture
If all else fails, you should be able to do it this way - produce an identical texture in the VSE but with the desired frame frozen and use that for your texture instead.
As far as I'm aware vers 2.8+ would still allow this.
Here is an original image sequence - 600 x 400.

...and after when paused midway through and re-rendered -  identical but with the freeze inserted.

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Details for those who may not know how -
The original sequence can be laid into a VSE strip and 'Split' with SH-K at the frame after the one to be frozen.
Select the sequence at the right of the split section and drag it out of the way.
Go back to the remaining left hand strip and select it's handle at it's right hand end.
Pull that to the right as far as needed.  This will freeze that frame.
Play it to get the frozen interval right, and once ok -
Select the frames you moved earlier and drag them back to join up with the stretched right hand end of the left strip.

Set the render output to the same pixel dimensions as the original but to a DIFFERENT folder.
Render this to the same format and dimension as the original and use that for your texture.
HINT - the VSE has a habit of acting up when making changes to it's strips, so each time a change is made, save the Blend file as something different, (increment?) exit Blender, then reload to try it out.